Assume you are a project cost engineer calculating the cost of a repetitive activity for your project. There are a total of 20 iterations of this activity required for the project. The project activity takes 2.5 hours at its steady rate and the learning rate is 75%. Calculate the initial output time for the first unit produced, using the learning curve formula:

Y=a^b

b=log decimal learning rate/log 2

I get the log decimal from the chart below (.288), but how do I figure out the value for log2?

Learning Curve Coefficient Table

	70%	75%	80%	85%
Unit Rate	Unit Time	Total Time	Unit Time	Total Time	Unit Time	Total Time	Unit Time	Total Time
5	.437	3.195	.513	3.459	.596	3.738	.686	4.031
10	.306	4.932	.385	5.589	.477	6.315	.583	7.116
15	.248	6.274	.325	7.319	.418	8.511	530	9.861
20	.214	7.407	.288	8.828	.381	10.485	.495	12.402